Disk drive devices are common information storage devices. FIG. 1a illustrates a conventional disk drive device and shows a magnetic disk 101 mounted on a spindle motor 102 for spinning the disk 101. A voice coil motor arm 104 carries a head gimbal assembly (HGA) 100 that includes a slider 103 incorporating a read/write transducer. A voice-coil motor (VCM, not labeled) is provided for controlling the motion of the motor arm 104 and, in turn, controlling the slider 103 to move from track to track across the surface of the disk 101, thereby enabling the read/write head to read data from or write data to the disk 101.
Now referring to FIG. 1b, the HGA 100 comprises a slider 103 having a reading/writing transducer imbedded therein, a suspension 190 to load or suspend the slider 103 thereon. As illustrated, the suspension 190 includes a load beam 106, a base plate 108, a hinge 107 and a flexure 105, all of which are assembled together.
In operation, a lift force is generated by the aerodynamic interaction between the slider 103 incorporating the read/write transducer and the spinning magnetic disk 101. The lift force is opposed by equal and opposite spring forces applied by the HGA 100 such that a predetermined flying height above the surface of the spinning disk 101 is maintained over a full radial stroke of the motor arm 104. A mounting hole 110 also is shown.
In a common disk drive unit, the slider flies only approximately a few micro-inches above the surface of the rotating disk. Generally, the flying height of the slider is considered as one of the most critical parameters affecting the disk reading and writing performances. More concretely, a relatively small flying height allows the transducers embedded in the slider to achieve a greater reading/writing resolution between different data bit locations on the disk surface, thus improving data storage capacity of the disk. Therefore, it is desired that the slider have a very small flying height to achieve a higher data storage capacity. At the same time, with the increasing popularity of lightweight and compact notebook type computers that utilize relatively small yet powerful disk drives, the need for a progressively lower and lower flying height has continually grown.
With reduction of the flying height, it is strongly expected that the flying height be kept constant all the time regardless of variable flying conditions, since great variation of flying height will deteriorate reading/writing performance of the slider, and in worse cases even result in data reading/writing failure. One of the facts that cause variation of flying height is thermal deformation of the suspension tongue. Specifically, when subjected to strong temperature changes, the suspension tongue will expand or contract, thus making the profile of the slider mounted thereon also deformed, and finally resulting in variation of the flying height. The flying height variation further badly affects the reading/writing performance of the slider. Therefore, it is necessary to control the deformation to a tolerant limit.
FIG. 1c is a partial top plan view of a typical flexure of the HGA shown in FIG. 1b, showing a structure of a suspension tongue of the flexure. As shown in FIG. 1c, several slots 128, 131, 133 with different shapes are formed in the suspension tongue 116 of the flexure 105 for releasing thermal deformation of the suspension tongue 116.
However, the structure of the suspension 190 described above is still sensitive to the thermal affect and apt to result in great variation of flying height of the slider, and also leads to high shock stresses at the bonding pads 126 and grounding pads 125.
Thus, there is a need for an improved suspension, head gimbal assembly, and disk drive unit that do not suffer from the above-mentioned drawbacks.